European Gravity Probe Launches Into Space

by Stephen Clark

Date: 17 March 2009 Time: 12:04 PM ET

European Gravity Probe Launches Into Space

ESA's GOCE gravity probe launched into orbit atop a Rockot booster from Russia's Plesetsk Cosmodrome on March 17, 2009.
CREDIT: ESA.

A modified Russian ballistic missile launched at 10:21 a.m. EDT (1421 GMT) today carrying a European probe that will measure the tug of Earth's gravity with finer detail than ever before.

The $450 million European satellite launched a day later than planned due to problems retracting the pad gantry.

The Gravity field and steady-state Ocean Circulation Explorer, or GOCE, launched atop a Rockot launcher at Complex 133 at the Plesetsk Cosmodrome in far northern Russia.

The Rockot is an SS-19 missile built to deliver nuclear warheads to targets across the globe. Eurockot, a Germany-based launch services firm, oversaw Tuesday's launch for the European Space Agency.

GOCE?s launch was postponed from September after rocket officials discovered a failure in the guidance and navigation system of the Rockot's Breeze KM upper stage. Technicians had to replace the rocket's gyroscope and refurbish its power system, delaying launch to this year.

Controllers will monitor the GOCE from the European Space Operations Center in Darmstadt, Germany.

The spacecraft carries an ultra-sensitive sensor to detect subtle variations in Earth's gravity field as it circles the planet in an unusually low orbit just 162 miles high.

Accurate maps of the gravity field will give scientists a crucial reference to compare against ocean circulation and sea level measurements.

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